how to add value in between two values in arays in javascript code example

Example 1: javascript range of integers

// n is your max range
[...Array(n).keys()]

let n = 10
[...Array(n).keys()] // [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Example 2: javascript range of integers

var list = [];
for (var i = lowEnd; i <= highEnd; i++) {
    list.push(i);
}